Aqueous formulations incorporating hydrophilic polymers and their use in hard surface cleaners are well known in the art. Hydrophilic polymers are known to provide anti-soiling and re-cleaning benefits on common household hard surfaces by imparting soil release properties thereto which facilitate subsequent cleaning.
For example, European Application No. 0467472 and U.S. Pat. Nos. 5,008,030, 6,926,745 describe hydrophilic polymers and their use in hard surface cleaners. The polymers described therein are cationic and are formed from trialkylammonium ethyl methacrylates.
Additionally, amphoteric polymers are also known to impart various benefits to hard surface cleaning compositions. U.S. Pat. No. 6,664,218 teaches amphoteric copolymers of diallyl dimethyl ammonium in combination with zwitterionic surfactants.
European Application No. 0522756 teaches the use of amphoteric polymers in hand dishwashing compositions.
Japanese Application No. 09-169995 teaches the use of acrylic acid/diallydimethylammonium copolymers for cleaning toilets.
U.S. Pat. Nos. 6,593,288, 6,767,410, 6,924,260 and PCT Application No. 2007/017098 teach amphoteric copolymers of diallyldimethyl ammonium and allege the importance of amphoterics which are characterized by an excess anionic charge.
U.S. Publication Application No. 2007/0105737 teaches the use of amphoterics exhibiting an excess anionic charge in combination with an acid to remove soap scum and limescale.
Fogging of surfaces arises when relatively cool non-porous surfaces are exposed to a warm moist atmosphere, since the cool surface will become fogged. In particular, glass fogging occurs by the condensation of steam or water vapor when the surface temperature of the non-porous surface is below the dewpoint. The opaque fog is therefore caused by the condensation of moisture droplets onto the non-porous surface. Naturally, this is undesirable for windows, mirrors, face masks, spectacles and the like.
One of the methods of avoiding fogging includes treating the non-porous surface with hydrophilic chemicals that tend to decrease the incidence of droplet formation. In general, hydrophilic chemicals are surface active agents which reduce the surface tension of the glass and encourage the individual water droplets to coalesce into a sheet.
U.S. Pat. No. 6,767,410 recognizes the ability of amphoteric copolymers with excess anionic charge to provide an anti-misting capability on surfaces such as glass. However, the described copolymers are not compatible in acidic systems.
Although multiple hydrophilic polymers, including amphoteric polymers have been described in the literature, there still exists a need for hydrophilic polymers which show compatibility in both basic and acidic hard surface cleaning formulations. Furthermore, it would be a great advantage if the said amphoteric polymers provided not only easier cleaning for surface soils such as hard water stains, soap scum, mud, food, toilet stains, oil, grease, particulates and the like but also simultaneously provided a long lasting anti-fog effect for said hard surfaces.
The present inventors have discovered particular hydrophilic terpolymers which are compatible in basic and acidic formulations which provide excellent hard surface cleaning capabilities such as soap scum removal and anti-fog effects is described in detail below.
The cleaning formulations incorporating the terpolymer form a film on the hard surface during the cleaning step which provides both a soil release and a soil resistant effect. Cleaning products containing these polymers will provide significant consumer benefit over existing products without soil release technology.
As mentioned above a particular advantage of these materials is their compatibility with a wide range of cleaning formulations, both acidic and basic, containing cationic, anionic or nonionic surfactants. Other commercially available polymers for surface cleaning formulations are often limited to specific cleaning formulation types and are not universally compatible.
The new materials provide a unique balance of cationic, anionic and hydrophilic properties to provide optimal cleaning performance. The materials are compatible in most types of cleaning formulations as a result of their low overall charge level. The slight excess of cationic charge allows them to bind to the surfaces being treated so that the materials create a semi-durable film that is stable to rinsing, yet will not cause long term build-up of residue. The hydrophilic nature of the materials provides excellent soil repellency and removal effects, as well as beneficial anti-fogging properties for windows, mirrors and other hard surfaces. The structure of the polymer also allows the properties of the polymer to be readily tuned to be appropriate for any type of cleaning formulation required.